We happened to have a few of these critters in the lab, as they were collected by Dr. Louise Page in the hopes that they would lay some egg masses for study. They are quite cryptic on the eelgrass (Zostera marina) where they are usually found, and they did lay egg masses on the Zostera. I didn't get pictures of the eggs, but the masses are small, flat and yellowish in colour. I have really been enjoying your web site; what a great resource!

Dear Nicole,
Thanks for this addition to the Forum. I remember being fascinated by this species when Bob Beeman sent me a reprint of his paper on the Californian anaspideans (Beeman, 1968). I spent many hours unsuccessfully trying to find a southern counterpart in the Zostera beds of New Zealand.

I have added a grey version of your photo alongside for those who don't realise this is a strange Sea Hare, which has a greatly modified shape so it can hide on sea grass leaves. The name Phyll [= leaf] aplysia is highly appropriate. In external shape, the head has the typical 2 pairs of tentacles [see Aplysioidea head Fact Sheet]. However the parapodia are very reduced [see Aplysioidea mantle cavity Fact Sheet] - they have been reduced to a small right flap between the inhalant and exhalant openings. The genital opening is just in front of the inhalant opening, and from it, the sperm groove runs forward to the penial sac just below the right rhinophore, as in other sea hares.
Best wishes,
Bill Rudman